Obtaining informed consent is a fundamental element of conducting ethical research. When a study requires the participation of adults who lack capacity to provide informed consent, such as persons who have dementia, investigators are faced with the ethical, legal and practical challenges of obtaining proxy consent and assent from potential participants. While the principle of respect for persons requires that those with diminished decisional capacity be given the opportunity to choose, to the extent they are able, whether to participate in research, consensus on the standards for assessing assent and dissent for research is lacking and no studies report the validity or reliability of standards to assess these abilities. This study has two specific aims: (1) identify the standards by which assent and dissent for research should be assessed in adults who lack capacity to give informed consent, and (2) based on those standards, generate a set of items that will form the basis of an instrument to assess assent and dissent in this population. This study will focus on assessing assent and dissent in persons who have dementia because of its high prevalence, its impact on society and the intense research effort directed toward persons at all stages of the syndrome. This study will use qualitative research methods, including interviews and focus group discussions with experts and other key informants on dementia, dementia research and research ethics, to define assent and dissent for research and identify standards for assessing assent and dissent in this population. These standards will be the criteria for measuring the decision making abilities needed to provide assent and for how to ethically respect dissent. Since empirical research on assent and dissent in adults is scarce, these methods provide data on which theory development and testing can be based. Scale development methods will be used to generate a set of items for an assessment instrument, the Assent and Dissent Assessment Tool (ADAT). The participating experts and other key informants will review and judge these items for content and face validity. This work serves as the foundation for future studies that will pilot test and finalize the ADAT and determine its reliability and criterion-related validity. Methods for accurately assessing assent and dissent for dementia research will increase the ability to protect the interests of potential study participants and support the ethical conduct of critical research. [unreadable] Project Narrative [unreadable] [unreadable] This study will focus on identifying standards for assessing assent and dissent for research in those who have dementia because of its high prevalence, its impact on society and the intense research effort directed toward it. Based on the standards identified, it will generate a set of measurement items that will form the basis for an instrument to assess assent and dissent for research in this population. Methods for accurately assessing assent and dissent for dementia research will increase our ability to protect the interests of potential study participants and support the ethical conduct of critical research. [unreadable] [unreadable] [unreadable]